package com.lefevre.cms.utils;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.io.ClassPathResource;

import java.io.*;
import java.util.*;

/**
 * CommentedProperties
 * 针对Properties进行扩展的工具类
 * <p>
 * 扩展的两个主要功能:
 * 1.对Properties文件中注释的保存。
 * CommentedProperties在读取和保存Properties文件时,会将其注释
 * 一起读取保存。CommentedProperties中会提供方法来根据key获取
 * 相应注释。在CommentedProperties中添加一个K-V对时，也会提供
 * 添加相应注释的方法。
 * <p>
 * 2.对Properties文件中Key值顺序的保证。
 * CommentedProperties会保证Key的顺序。从一个Properties文件中
 * 读取所有K-V对，保存到另一个Properties文件时，Key的顺序不会
 * 改变。
 *
 * @author BrokenDreams
 */
public class CommentedProperties {
    private static final Logger logger = LoggerFactory.getLogger(CommentedProperties.class);
    private static final String BLANK = "";
    /**
     * A table of hex digits
     */
    private static final char[] hexDigit = {
            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
    };
    //读取富文本编辑器允许图片上传格式
    private static List<String> imageUploadFormatList = null;
    //读取富文本编辑器允许文件上传格式
    private static List<String> fileUploadFormatList = null;
    //读取富文本编辑器允许视频上传格式
    private static List<String> videoUploadFormatList = null;
    //富文本嵌入视频地址白名单
    private static List<String> embedVideoWhiteList = null;
    //OAuth2配置参数
    private static Map<String, Object> oauth2Map = null;
    /**
     * 内部属性表
     */
    private final Properties props;
    /**
     * 保存key与comment的映射，
     * 同时利用这个映射来保证key的顺序。
     */
    private final LinkedHashMap<String, String> keyCommentMap = new LinkedHashMap<>();

    public CommentedProperties() {
        super();
        props = new Properties();
    }

    public CommentedProperties(Properties defaults) {
        super();
        props = new Properties(defaults);
    }

    private static void writeComments(BufferedWriter bw, String comments)
            throws IOException {
        bw.write("#");
        int len = comments.length();
        int current = 0;
        int last = 0;
        while (current < len) {
            char c = comments.charAt(current);
            if (c > '\u00ff' || c == '\n' || c == '\r') {
                if (last != current)
                    bw.write(comments.substring(last, current));
                if (c > '\u00ff') {
                    bw.write(c);
                } else {
                    bw.newLine();
                    if (c == '\r' &&
                            current != len - 1 &&
                            comments.charAt(current + 1) == '\n') {
                        current++;
                    }
                    if (current == len - 1 ||
                            (comments.charAt(current + 1) != '#' &&
                                    comments.charAt(current + 1) != '!'))
                        bw.write("#");
                }
                last = current + 1;
            }
            current++;
        }
        if (last != current)
            bw.write(comments.substring(last, current));
        bw.newLine();
    }

    /**
     * Convert a nibble to a hex character
     *
     * @param nibble the nibble to convert.
     */
    private static char toHex(int nibble) {
        return hexDigit[(nibble & 0xF)];
    }

    /**
     * 读取富文本编辑器允许图片上传格式
     *
     * @return
     */
    public static List<String> readRichTextAllowImageUploadFormat() {
        if (imageUploadFormatList != null && imageUploadFormatList.size() > 0) {
            return imageUploadFormatList;
        }
        //富文本图片上传格式
        List<String> _imageUploadFormatList = new ArrayList<>();


        org.springframework.core.io.Resource resource = new ClassPathResource("/richText.properties");//读取配置文件
        CommentedProperties props = new CommentedProperties();

        try {
            props.load(resource.getInputStream(), "utf-8");

            Set<String> propertyNameList = props.propertyNames();
            if (propertyNameList != null && propertyNameList.size() > 0) {
                for (String propertyName : propertyNameList) {
                    if (propertyName.trim().equals("imageUploadFormat")) {
                        String value = props.getProperty(propertyName.trim());
                        if (value != null && !"".equals(value.trim())) {
                            String[] values = value.trim().split(",");
                            if (values.length > 0) {
                                for (String format : values) {
                                    if (format != null && !"".equals(format.trim())) {
                                        _imageUploadFormatList.add(format.trim());
                                    }

                                }
                            }
                        }
                    }
                }
                imageUploadFormatList = _imageUploadFormatList;
            }
        } catch (IOException e) {
            logger.error("读取配置文件richText.properties错误", e);
        }
        return _imageUploadFormatList;

    }

    /**
     * 读取富文本编辑器允许文件上传格式
     *
     * @return
     */
    public static List<String> readRichTextAllowFileUploadFormat() {
        if (fileUploadFormatList != null && fileUploadFormatList.size() > 0) {
            return fileUploadFormatList;
        }
        //富文本文件上传格式
        List<String> _fileUploadFormatList = new ArrayList<>();
        //读取配置文件
        org.springframework.core.io.Resource resource = new ClassPathResource("/richText.properties");
        CommentedProperties props = new CommentedProperties();
        try {
            props.load(resource.getInputStream(), "utf-8");
            Set<String> propertyNameList = props.propertyNames();
            if (propertyNameList != null && propertyNameList.size() > 0) {
                for (String propertyName : propertyNameList) {
                    if (propertyName.trim().equals("fileUploadFormat")) {
                        String value = props.getProperty(propertyName.trim());
                        if (value != null && !"".equals(value.trim())) {
                            String[] values = value.trim().split(",");
                            if (values.length > 0) {
                                for (String format : values) {
                                    if (format != null && !"".equals(format.trim())) {
                                        _fileUploadFormatList.add(format.trim());
                                    }
                                }
                            }
                        }
                    }
                }
                fileUploadFormatList = _fileUploadFormatList;
            }

        } catch (IOException e) {
            logger.error("读取配置文件richText.properties错误", e);
        }
        return _fileUploadFormatList;

    }

    /**
     * 读取富文本编辑器允许视频上传格式
     *
     * @return
     */
    public static List<String> readRichTextAllowVideoUploadFormat() {
        if (videoUploadFormatList != null && videoUploadFormatList.size() > 0) {
            return videoUploadFormatList;
        }
        //富文本视频上传格式
        List<String> _videoUploadFormatList = new ArrayList<>();

        org.springframework.core.io.Resource resource = new ClassPathResource("/richText.properties");//读取配置文件
        CommentedProperties props = new CommentedProperties();

        try {
            props.load(resource.getInputStream(), "utf-8");

            Set<String> propertyNameList = props.propertyNames();
            if (propertyNameList != null && propertyNameList.size() > 0) {
                for (String propertyName : propertyNameList) {
                    if (propertyName.trim().equals("videoUploadFormat")) {
                        String value = props.getProperty(propertyName.trim());
                        if (value != null && !"".equals(value.trim())) {
                            String[] values = value.trim().split(",");
                            if (values.length > 0) {
                                for (String format : values) {
                                    if (format != null && !"".equals(format.trim())) {
                                        _videoUploadFormatList.add(format.trim());
                                    }
                                }
                            }
                        }
                    }
                }
                videoUploadFormatList = _videoUploadFormatList;
            }
        } catch (IOException e) {
            logger.error("读取配置文件richText.properties错误", e);
        }
        return _videoUploadFormatList;
    }

    /**
     * 读取富文本编辑器嵌入视频地址白名单
     *
     * @return
     */
    public static List<String> readRichTextAllowEmbedVideoWhiteList() {
        if (embedVideoWhiteList != null && embedVideoWhiteList.size() > 0) {
            return embedVideoWhiteList;
        }
        //嵌入视频地址白名单
        List<String> _embedVideoWhiteList = new ArrayList<>();

        org.springframework.core.io.Resource resource = new ClassPathResource("/richText.properties");//读取配置文件
        CommentedProperties props = new CommentedProperties();
        try {
            props.load(resource.getInputStream(), "utf-8");

            Set<String> propertyNameList = props.propertyNames();
            if (propertyNameList != null && propertyNameList.size() > 0) {
                for (String propertyName : propertyNameList) {
                    if (propertyName.trim().equals("embedVideoWhite")) {
                        String value = props.getProperty(propertyName.trim());
                        if (value != null && !"".equals(value.trim())) {
                            String[] values = value.trim().split(",");
                            if (values.length > 0) {
                                for (String format : values) {
                                    if (format != null && !"".equals(format.trim())) {
                                        _embedVideoWhiteList.add(format.trim());
                                    }
                                }
                            }
                        }
                    }
                }
                embedVideoWhiteList = _embedVideoWhiteList;
            }
        } catch (IOException e) {
            logger.error("读取配置文件richText.properties错误", e);
        }
        return _embedVideoWhiteList;
    }

    /**
     * 读取oauth2.properties参数
     *
     * @return
     */
    public static Map<String, Object> readOAuth2() {
        if (oauth2Map != null && oauth2Map.size() > 0) {
            return oauth2Map;
        }
        //OAuth2配置参数
        Map<String, Object> _oauth2Map = new HashMap<>();
        org.springframework.core.io.Resource resource = new ClassPathResource("/oauth2.properties");//读取配置文件
        CommentedProperties props = new CommentedProperties();
        try {
            props.load(resource.getInputStream(), "utf-8");
            Set<String> propertyNameList = props.propertyNames();
            if (propertyNameList != null && propertyNameList.size() > 0) {
                for (String propertyName : propertyNameList) {
                    switch (propertyName.trim()) {
                        case "oauth2.secret": {
                            String value = props.getProperty(propertyName.trim());
                            if (value != null && !"".equals(value.trim())) {
                                _oauth2Map.put("secret", value.trim());
                            } else {//如果为空，则密钥为随机数
                                _oauth2Map.put("secret", UUIDUtil.getUUID32());
                            }
                            break;
                        }
                        case "oauth2.accessTokenValiditySeconds": {
                            String value = props.getProperty(propertyName.trim());
                            if (value != null && !"".equals(value.trim())) {
                                _oauth2Map.put("accessTokenValiditySeconds", Integer.parseInt(value.trim()));
                            }
                            break;
                        }
                        case "oauth2.refreshTokenValiditySeconds": {
                            String value = props.getProperty(propertyName.trim());
                            if (value != null && !"".equals(value.trim())) {
                                _oauth2Map.put("refreshTokenValiditySeconds", Integer.parseInt(value.trim()));
                            }
                            break;
                        }
                        case "oauth2.loginFailureNumber": {
                            String value = props.getProperty(propertyName.trim());
                            if (value != null && !"".equals(value.trim())) {
                                _oauth2Map.put("loginFailureNumber", Integer.parseInt(value.trim()));
                            }
                            break;
                        }
                    }
                }
                oauth2Map = _oauth2Map;
            }
        } catch (IOException e) {
            logger.error("读取配置文件oauth2.properties错误", e);
        }
        return _oauth2Map;
    }

    /**
     * 设置一个属性，如果key已经存在，那么将其对应value值覆盖。
     *
     * @param key
     * @param value
     * @return
     */
    public String setProperty(String key, String value) {
        return setProperty(key, value, BLANK);
    }

    /**
     * 设置一个属性，如果key已经存在，那么将其对应value值覆盖。
     *
     * @param key     键
     * @param value   与键对应的值
     * @param comment 对键值对的说明
     * @return
     */
    public synchronized String setProperty(String key, String value, String comment) {
        Object oldValue = props.setProperty(key, value);
        if (BLANK.equals(comment)) {
            if (!keyCommentMap.containsKey(key)) {
                keyCommentMap.put(key, comment);
            }
        } else {
            keyCommentMap.put(key, comment);
        }
        return (String) oldValue;
    }

    /**
     * 根据key获取属性表中相应的value。
     *
     * @param key
     * @return
     */
    public String getProperty(String key) {
        return props.getProperty(key);
    }

    /**
     * 根据key获取属性表中相应的value。
     * 如果没找到相应的value，返回defaultValue。
     *
     * @param key
     * @param defaultValue
     * @return
     */
    public String getProperty(String key, String defaultValue) {
        return props.getProperty(key, defaultValue);
    }

    /**
     * 从一个字符流中读取属性到属性表中
     *
     * @param reader
     * @throws IOException
     */
    public synchronized void load(Reader reader) throws IOException {
        load0(new LineReader(reader));
    }

    /**
     * 从一个字节流中读取属性到属性表中
     *
     * @param inStream
     * @throws IOException
     */
    public synchronized void load(InputStream inStream) throws IOException {
        load0(new LineReader(inStream));
    }

    /**
     * 从一个字节流中读取属性到属性表中
     *
     * @param inStream
     * @param charset
     * @throws IOException
     */
    public synchronized void load(InputStream inStream, String charset) throws IOException {
        InputStreamReader reader = new InputStreamReader(inStream, charset);
        load0(new LineReader(reader));
    }

    /**
     * 从一个文件中读取属性到属性表中
     *
     * @param file    属性文件
     * @param charset 字符集
     * @throws IOException
     */
    public synchronized void load(File file, String charset) throws IOException {
        FileInputStream inputStream = new FileInputStream(file);
        InputStreamReader reader = new InputStreamReader(inputStream, charset);
        load0(new LineReader(reader));
    }

    /**
     * 从一个文件中读取属性到属性表中
     * 默认字符集为utf-8
     *
     * @param file 属性文件
     * @throws IOException
     */
    public synchronized void load(File file) throws IOException {
        FileInputStream inputStream = new FileInputStream(file);
        InputStreamReader reader = new InputStreamReader(inputStream, "utf-8");
        load0(new LineReader(reader));
    }

    /**
     * 将属性表中的属性写到字符流里面。
     *
     * @param writer
     * @throws IOException
     */
    public void store(Writer writer) throws IOException {
        store0((writer instanceof BufferedWriter) ? (BufferedWriter) writer
                : new BufferedWriter(writer), false);
    }

    /**
     * 将属性表中的属性写到字符流里面。
     *
     * @param bufferedWriter
     * @throws IOException
     */
    public void store(BufferedWriter bufferedWriter) throws IOException {
        store0(bufferedWriter, false);
    }

    /**
     * 将属性表中的属性写到字节流里面。
     *
     * @param out
     * @throws IOException
     */
    public void store(OutputStream out) throws IOException {
        store0(new BufferedWriter(new OutputStreamWriter(out, "utf-8")), true);
    }

    /**
     * 如果属性表中某个key对应的value值和参数value相同
     * 那么返回true，否则返回false。
     *
     * @param value
     * @return
     */
    public boolean containsValue(String value) {
        return props.containsValue(value);
    }

    /**
     * 如果属性表中存在参数key，返回true，否则返回false。
     *
     * @param key
     * @return
     */
    public boolean containsKey(String key) {
        return props.containsKey(key);
    }

    /**
     * 获取属性表中键值对数量
     *
     * @return
     */
    public int size() {
        return props.size();
    }

    /**
     * 检查属性表是否为空
     *
     * @return
     */
    public boolean isEmpty() {
        return props.isEmpty();
    }

    /**
     * 清空属性表
     */
    public synchronized void clear() {
        props.clear();
        keyCommentMap.clear();
    }

    /**
     * 获取属性表中所有key的集合。
     *
     * @return
     */
    public Set<String> propertyNames() {
        return props.stringPropertyNames();
    }

    public synchronized String toString() {
        StringBuffer buffer = new StringBuffer();
        Iterator<Map.Entry<String, String>> kvIter = keyCommentMap.entrySet().iterator();
        buffer.append("[");
        while (kvIter.hasNext()) {
            buffer.append("{");
            Map.Entry<String, String> entry = kvIter.next();
            String key = entry.getKey();
            String val = getProperty(key);
            String comment = entry.getValue();
            buffer.append("key=" + key + ",value=" + val + ",comment=" + comment);
            buffer.append("}");
        }
        buffer.append("]");
        return buffer.toString();
    }

    public boolean equals(Object o) {
        //不考虑注释说明是否相同
        return props.equals(o);
    }

    public int hashCode() {
        return props.hashCode();
    }

    private void load0(LineReader lr) throws IOException {
        char[] convtBuf = new char[1024];
        int limit;
        int keyLen;
        int valueStart;
        char c;
        boolean hasSep;
        boolean precedingBackslash;
        StringBuffer buffer = new StringBuffer();

        while ((limit = lr.readLine()) >= 0) {
            c = 0;
            keyLen = 0;
            valueStart = limit;
            hasSep = false;
            //获取注释
            c = lr.lineBuf[keyLen];
            if (c == '#' || c == '!') {
                String comment = loadConvert(lr.lineBuf, 1, limit - 1, convtBuf);
                if (buffer.length() > 0) {
                    buffer.append("\n");
                }
                buffer.append(comment);
                continue;
            }
            precedingBackslash = false;
            while (keyLen < limit) {
                c = lr.lineBuf[keyLen];
                //need check if escaped.
                if ((c == '=' || c == ':') && !precedingBackslash) {
                    valueStart = keyLen + 1;
                    hasSep = true;
                    break;
                } else if ((c == ' ' || c == '\t' || c == '\f') && !precedingBackslash) {
                    valueStart = keyLen + 1;
                    break;
                }
                if (c == '\\') {
                    precedingBackslash = !precedingBackslash;
                } else {
                    precedingBackslash = false;
                }
                keyLen++;
            }
            while (valueStart < limit) {
                c = lr.lineBuf[valueStart];
                if (c != ' ' && c != '\t' && c != '\f') {
                    if (!hasSep && (c == '=' || c == ':')) {
                        hasSep = true;
                    } else {
                        break;
                    }
                }
                valueStart++;
            }
            String key = loadConvert(lr.lineBuf, 0, keyLen, convtBuf);
            String value = loadConvert(lr.lineBuf, valueStart, limit - valueStart, convtBuf);
            setProperty(key, value, buffer.toString());
            //reset buffer
            buffer = new StringBuffer();
        }
    }

    /*
     * Converts encoded &#92;uxxxx to unicode chars
     * and changes special saved chars to their original forms
     */
    private String loadConvert(char[] in, int off, int len, char[] convtBuf) {
        if (convtBuf.length < len) {
            int newLen = len * 2;
            if (newLen < 0) {
                newLen = Integer.MAX_VALUE;
            }
            convtBuf = new char[newLen];
        }
        char aChar;
        char[] out = convtBuf;
        int outLen = 0;
        int end = off + len;

        while (off < end) {
            aChar = in[off++];
            if (aChar == '\\') {
                aChar = in[off++];
                if (aChar == 'u') {
                    // Read the xxxx
                    int value = 0;
                    for (int i = 0; i < 4; i++) {
                        aChar = in[off++];
                        switch (aChar) {
                            case '0':
                            case '1':
                            case '2':
                            case '3':
                            case '4':
                            case '5':
                            case '6':
                            case '7':
                            case '8':
                            case '9':
                                value = (value << 4) + aChar - '0';
                                break;
                            case 'a':
                            case 'b':
                            case 'c':
                            case 'd':
                            case 'e':
                            case 'f':
                                value = (value << 4) + 10 + aChar - 'a';
                                break;
                            case 'A':
                            case 'B':
                            case 'C':
                            case 'D':
                            case 'E':
                            case 'F':
                                value = (value << 4) + 10 + aChar - 'A';
                                break;
                            default:
                                throw new IllegalArgumentException(
                                        "Malformed \\uxxxx encoding.");
                        }
                    }
                    out[outLen++] = (char) value;
                } else {
                    if (aChar == 't') aChar = '\t';
                    else if (aChar == 'r') aChar = '\r';
                    else if (aChar == 'n') aChar = '\n';
                    else if (aChar == 'f') aChar = '\f';
                    out[outLen++] = aChar;
                }
            } else {
                out[outLen++] = (char) aChar;
            }
        }
        return new String(out, 0, outLen);
    }

    private void store0(BufferedWriter bw, boolean escUnicode)
            throws IOException {
        synchronized (this) {
            Iterator<Map.Entry<String, String>> kvIter = keyCommentMap.entrySet().iterator();
            while (kvIter.hasNext()) {
                Map.Entry<String, String> entry = kvIter.next();
                String key = entry.getKey();
                String val = getProperty(key);
                String comment = entry.getValue();
                key = saveConvert(key, true, escUnicode);
                /* No need to escape embedded and trailing spaces for value, hence
                 * pass false to flag.
                 */
                val = saveConvert(val, false, escUnicode);
                if (!comment.equals(BLANK))
                    writeComments(bw, comment);
                bw.write(key + "=" + val);
                bw.newLine();
            }
        }
        bw.flush();
    }

    /*
     * Converts unicodes to encoded &#92;uxxxx and escapes
     * special characters with a preceding slash
     */
    private String saveConvert(String theString,
                               boolean escapeSpace,
                               boolean escapeUnicode) {
        int len = theString.length();
        int bufLen = len * 2;
        if (bufLen < 0) {
            bufLen = Integer.MAX_VALUE;
        }
        StringBuffer outBuffer = new StringBuffer(bufLen);

        for (int x = 0; x < len; x++) {
            char aChar = theString.charAt(x);
            // Handle common case first, selecting largest block that
            // avoids the specials below
            if ((aChar > 61) && (aChar < 127)) {
                if (aChar == '\\') {
                    outBuffer.append('\\');
                    outBuffer.append('\\');
                    continue;
                }
                outBuffer.append(aChar);
                continue;
            }
            switch (aChar) {
                case ' ':
                    if (x == 0 || escapeSpace)
                        outBuffer.append('\\');
                    outBuffer.append(' ');
                    break;
                case '\t':
                    outBuffer.append('\\');
                    outBuffer.append('t');
                    break;
                case '\n':
                    outBuffer.append('\\');
                    outBuffer.append('n');
                    break;
                case '\r':
                    outBuffer.append('\\');
                    outBuffer.append('r');
                    break;
                case '\f':
                    outBuffer.append('\\');
                    outBuffer.append('f');
                    break;
                case '=': // Fall through
                case ':': // Fall through
                case '#': // Fall through
                case '!':
                    outBuffer.append('\\');
                    outBuffer.append(aChar);
                    break;
                default:
                    if (((aChar < 0x0020) || (aChar > 0x007e)) & escapeUnicode) {
                        outBuffer.append('\\');
                        outBuffer.append('u');
                        outBuffer.append(toHex((aChar >> 12) & 0xF));
                        outBuffer.append(toHex((aChar >> 8) & 0xF));
                        outBuffer.append(toHex((aChar >> 4) & 0xF));
                        outBuffer.append(toHex(aChar & 0xF));
                    } else {
                        outBuffer.append(aChar);
                    }
            }
        }
        return outBuffer.toString();
    }

    /*
     * 基于java.util.Properties.LineReader进行改造
     *
     * Read in a "logical line" from an InputStream/Reader, skip all comment
     * and blank lines and filter out those leading whitespace characters
     * (\u0020, \u0009 and \u000c) from the beginning of a "natural line".
     * Method returns the char length of the "logical line" and stores
     * the line in "lineBuf".
     */
    class LineReader {
        byte[] inByteBuf;
        char[] inCharBuf;
        char[] lineBuf = new char[1024];
        int inLimit = 0;
        int inOff = 0;
        InputStream inStream;
        Reader reader;
        public LineReader(InputStream inStream) {
            this.inStream = inStream;
            inByteBuf = new byte[8192];
        }
        public LineReader(Reader reader) {
            this.reader = reader;
            inCharBuf = new char[8192];
        }

        int readLine() throws IOException {
            int len = 0;
            char c = 0;

            boolean skipWhiteSpace = true;
            boolean isNewLine = true;
            boolean appendedLineBegin = false;
            boolean precedingBackslash = false;
            boolean skipLF = false;

            while (true) {
                if (inOff >= inLimit) {
                    inLimit = (inStream == null) ? reader.read(inCharBuf)
                            : inStream.read(inByteBuf);
                    inOff = 0;
                    if (inLimit <= 0) {
                        if (len == 0) {
                            return -1;
                        }
                        return len;
                    }
                }
                if (inStream != null) {
                    //The line below is equivalent to calling a
                    //ISO8859-1 decoder.
                    c = (char) (0xff & inByteBuf[inOff++]);
                } else {
                    c = inCharBuf[inOff++];
                }
                if (skipLF) {
                    skipLF = false;
                    if (c == '\n') {
                        continue;
                    }
                }
                if (skipWhiteSpace) {
                    if (c == ' ' || c == '\t' || c == '\f') {
                        continue;
                    }
                    if (!appendedLineBegin && (c == '\r' || c == '\n')) {
                        continue;
                    }
                    skipWhiteSpace = false;
                    appendedLineBegin = false;
                }
                if (isNewLine) {
                    isNewLine = false;
                }

                if (c != '\n' && c != '\r') {
                    lineBuf[len++] = c;
                    if (len == lineBuf.length) {
                        int newLength = lineBuf.length * 2;
                        if (newLength < 0) {
                            newLength = Integer.MAX_VALUE;
                        }
                        char[] buf = new char[newLength];
                        System.arraycopy(lineBuf, 0, buf, 0, lineBuf.length);
                        lineBuf = buf;
                    }
                    //flip the preceding backslash flag
                    if (c == '\\') {
                        precedingBackslash = !precedingBackslash;
                    } else {
                        precedingBackslash = false;
                    }
                } else {
                    // reached EOL
                    if (len == 0) {
                        isNewLine = true;
                        skipWhiteSpace = true;
                        len = 0;
                        continue;
                    }
                    if (inOff >= inLimit) {
                        inLimit = (inStream == null)
                                ? reader.read(inCharBuf)
                                : inStream.read(inByteBuf);
                        inOff = 0;
                        if (inLimit <= 0) {
                            return len;
                        }
                    }
                    if (precedingBackslash) {
                        len -= 1;
                        //skip the leading whitespace characters in following line
                        skipWhiteSpace = true;
                        appendedLineBegin = true;
                        precedingBackslash = false;
                        if (c == '\r') {
                            skipLF = true;
                        }
                    } else {
                        return len;
                    }
                }
            }
        }
    }

}
